Portable derrick or mast



June 195] c. E. SOMMARSTROM 2,5 6, 48

PORTABLE DERRICK OR MAST Filed May 26, 1947 2 Sheets-Sheet l June 1951 c. E. SOMMARSTROM ,948 I PORTABLE DERRICK 0R MAST v2 Sheets$heet 2 Filed May 26, 1947 INVENTOR. WM

QTTOBNEY Patented June 12, T951 UNITED STATES PATENT OFFICE PORTABLE DERRICK R MAST Olifiord E. Sommarstrom, HollydalefCalifl, as-

signor to Waldrip Engineering '00., Hollydale, Calif a corporation of California Application May 26, 1947, Serial No. 750,551

Claims.

This invention relates to a portable derrick or mast that may be used either for drilling or servicing oil wells and the like.

A primary object of the invention is to provide an improved mast or derrick composed of two legs which may or may not be extensible and which are adapted to be independently or separately erected to upright positions at the well site and to provide a novel and simple means for connecting the legs at the tops thereof so that a crown block consisting of a crown block shaft and sheaves will be mutually supported by the legs so as to have the loads imposed thereon distributed between the legs.

More specifically, an object of the invention is to provide a portable derrick or mast consisting of two legs adapted to be erected into upright positions wherein the crown block shaft is mounted on one of the legs so as to be elevated thereby.

The other leg carries parts or portions adapted to supportingly engage the crown block shaft when it is erected and both legs have mutually engaging portions adapted to mutually abut about the crown block shaft. These latter portions are then looked against separation by an axially movable collar on each end of the crown block shaft so that thelegs are effectively connected together at their tops and the loads are equally distributed thereon.

Still another object of the invention is to provvide a novel method and apparatus for erecting illustrating the two legs of the improved derrick or mast in their collapsed and portable position and illustrating them as being located with respect to a well site;

Fig. 2 is a similar view to Fig. 1 but illustrating the legs as having been erected, in full lines, and illustrating in dotted lines the manner of erection of the second le Fig. 3 is a partial view in side elevationillustrating the tops of the two'legs of the derrick or mast;

Fig. 4 is a top plan view of the connected tops of the legs and may be regarded as having been taken upon the line 44 upon Fig. 3;

Fig. 5 is a sectional view taken substantially upon the line 55 upon Fig. 4; and

Figs. 6 and 7 are sectional views taken substantially upon the lines 66 and 1-'! upon Fig. 4, respectively.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the improved derrick or mast consists primarily of two legs. These legs are extensible and are made up of telescopic leg sections. The lower leg sections are indicated at In and l l, respectively, and the upper leg sections are indicated at l2 and 13. These upper leg sections are designed to telescope downwardly within their respective lower leg sections. The particular design of the leg sections is immaterial in so far as the present invention is concerned although they have been illustrated as being made up of cornices, girts and braces or lacing connecting the cornices. Each of the lower leg sections is pivotally mounted as at I 4 and I5, respectively, on its trailer indicated at It and Il. These trailers are adapted to be moved to the well site such as by tractors or trucks, indicated at It and Hi. When the legs have been properly positioned by means of their trailers l6 and I! on opposite sides of the well site, the lower le section it, together with its collapsed or enclosed upper leg section I2, is erected into an upright position and the upper leg section 12 is then extended or elevated into its upper position as illustrated in Fig. 2, and locked in such extended position. The particular means employed to turn the lower leg section H] from its horizontal or prone position illustrated in Fig. 1, to the upright position shown in Fig. 2, and the particular means employed for extending and. locking the upper leg section l2 in its uppermost position, form no part of the present invention and consequently they are neither illustrated nor described herein. Any conventional or preferred means may be employed for this purpose. The upper leg section l2 has a pair of sheaves 20 and 2! rotatably mounted thereon adjacent its cornices and a bridle 22 is trained over these sheaves and is adapted to be connected to the top of the upper leg section I3. A cable 23, such as a sand line, may then be wound up on a draw works 24 to swing the lower leg section I I about its pivot i5 into an upright position and to lift the upper leg section l3 into its uppermost or extended position.- In this manner the second leg, which is composed of the leg sections II and [3, can be elevated by means of the first leg so that it is unnecessary to equip the trailer ll with a draw 21 protrude laterally beyond the side of the leg section I2 and have apertures 28 therein to receive a crown block shaft 29. This crown block shaft is stationarily mounted on the plates 25 so as to be elevated with the upper leg section l2 of the first leg. Crown block sheaves 30 are rotatably mounted on the crown block shaft for rotation relatively thereto, suitable anti-friction barings being provided as indicated at 3I. The intermediate plates 26 have the configuration illustrated in Fig. '7 wherein there are hooked portions 32 that project laterally from the side of the leg section I3 so as to engage beneath the crown block shaft 29 to assist in supporting it.

Near the ends of the crown block shaft 29 the upper leg section I2 has rigidly mounted thereon plates 33 and in a similar manner the upper leg section I3 has opposed plates 34. The plates 33 and 34 are arranged in the same plane and are adapted to mutually abut each other about the crown block shaft 29 as at 35. These plates have split sleeve sections 36 and 31 welded or otherwise rigidly secured thereto. These split sleeve sections are semi-cylindrical in form so as to fit snugly about the crown block shaft and have their external surfaces taper outwardly toward the ends of the crown block shaft. On each end of the shaft 29 there is an axially movable collar 38 which is internally tapered and which is slidable on the crown block shaft onto the sleeve sections 36 and 31 so as to bind these sleeve sections together and thus lock the two legs against separation. As a means of forcing the collar 36 axially on the shaft 29 the end of the shaft is threaded, as indicated at 39, to receive a nut 43 which has a rotatable connection 4| with the collar. Thus when the two legs of the derrick have been elevated, causing the hooked portions 32 on the plates 26 to engage beneath the crown block shaft and causing the split sleeve sections 36 and 37 to mutually abut each other adjacent the ends of the shaft, the nuts 40 can then be rotated to force the internally tapered collar onto the externally tapered sleeve sections 36 and 31 and thus tighten the upper ends of the legs into a rigid structure. When it is desired to lower the mast it is merely necessary to reversely rotate the nuts 40 to withdraw the collar 33 from about the split sleeve sections 33 and 31. This releases the connection between the two leg sections I2 :2

and I3 and enables the legs to be collapsed and lowered independently of each other. The cable and traveling block may be suspended from the sheaves 33 of the crown block in any conventional or preferred manner.

In addition to the connection between the legs afforded by the collars 38 and the split sleeve sections 33 and 31, the cornices of the upper leg section I2 may be provided with suitable fittings such as those indicated at 42 designed to engage the cornices of the opposed leg section and thus hold the two legs against displacement in a direction longitudinally of the crown block shaft.

From the above described construction it will be appreciated that an improved portable derrick or mast has been provided which when erected provides a very firm connection between the two legs of the mast and in such a manner that loads applied to the crown block shaft 29 will be distributed between the two legs.

In actual operation it frequently is desirable to elevate or extend both legs to a height 01' elevation above the height that they will ultimately assume in order to facilitate the mutual engagement between the tops of the legs. When this has been effected the extensions I2 and I3 may be allowed to descend slightly to their ultimate positions wherein the load imposed upon the crown block shaft will be equally distributed between the two legs.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A derrick comprising two legs adapted to be erected into upright positions, a crown block shaft mounted upon one of the legs, said legs carrying portions adapted to mutually abut each other about the crown block shaft, said portions carrying sections of split sleeves adapted to abut each other about the crown block shaft, and collars axially movable on the crown block shaft adapted to engage the sections of the split sleeve and lock them against separation.

2. A derrick comprising two legs adapted to be erected into upright positions, a crown block shaft mounted upon one of the legs, said legs carrying portions adapted to mutually abut each other about the crown block shaft, said portions carrying split sleeve sections adapted to cooperatively fit about the crown block shaft, collars on the crown block shaft adapted to be axially movable thereon to enclose said sections to lock them against separation, and means threaded onto the shaft for forcing said collars into enclosing engagement with the sleeve sections.

3. Means for connecting two legs of a derrick between which a crown block having a crown block shaft is to be supported comprising mutually engageable parts on the legs adapted to mutually engage about a crown block shaft, split sleeve sections carried by said parts adapted to fit about the shaft, and means axially movable upon the shaft engageable with said sections for locking said parts against separation.

4. A derrick comprising two legs adapted to be erected into upright positions, alternate plates carried by one leg and having a crown block shaft extending therethrough, intermediate plates carried by the other leg engageable with the under side of the crown block shaft, there being end plates carried by each of the legs adapted to mutually abut about the crown block shaft, and means for locking said end plates against separation.

5. A derrick comprising two legs adapted to be erected into upright positions, alternate plates carried by one leg and having a crown block shaft extending therethrough, intermediate plates carried by the other leg engageable with the under side of the crown block shaft, there being end piates carried by each of the legs adapted to mutually abut about the crown block shaft, and sheaves rotatable on the crown block shaft between the alternate and intermediate plates.

CLIFFORD E. SOMMARSTROM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 670,674 Hutchins Mar. 26, 1901 2,133,367 Johansen Dec. 19, 1939 2,316,304 Wilson Apr. 13, 1943 2,336,305 Selberg et a1 Dec. '7, 1943 

